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D-Link DHP-306AV

D-Link DHP-306AV powerline Ethernet adaptor

Network your mains cabling

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Review I use a couple of Devolo dLAN AVplus powerline Ethernet adaptors at home, to hook up my wired-only Sony Bravia connected telly to my router. They're great adaptors, but with a pass-through three-pin power socket, they're bulky. D-Link's latest adaptor, the DHP-306AV, offers a more compact alternative.

D-Link DHP-306AV

D-Link's DHP-306AV: compact

You'd not know it from the box, or the adaptor itself, but the D-Link adheres to the HomePlug AV powerline standard, which provides throughputs of up to 200Mb/s over mains wiring.

Like all other 200Mb/s adaptors - even those based on the rival Universal Powerline standard - this one sports a 100Mb/s Ethernet port because there's no way that in the real world you're going to get speeds anywhere near the maximum, which is the raw speed before error correction and data-exchange protocols have taken up bandwidth, let alone the impact of noise on the line.

The throughput you actually get depends on the state of your electric wiring, what other devices you have plugged in, how far apart your adaptors are and so on. I did a file-transfer test, uploading and downloading a movie file to and from a network hard drive and got a reasonable average of 62Mb/s, which is pretty much what I get with the Devolo adaptors.

D-Link DHP-306AV

The Ethernet port is on the side... but still only 100Mb/s

The D-Link adaptor has push-button encryption: press the key on each adaptor and they'll jointly agree on and share a 128-bit AES encryption key. Or you can set your own using the utility D-Link bundles with the DHP-306AV. Nicely, the utility lets you give names to each adaptor, the better to see which one each one on this list is: 'living room', 'router' etc.

Next page: Energy star

Radio 4 FM isn't going to be affected by these

But Ambulance services, the Police, Military etc etc all use shortwave radios, and these devices defecate all over that spectrum.

Let me repeat that, the interference these devices cause you probably won't see, which is one of the problems. "Hey, it works for me, so why should I care?"

"The D-Link adaptor has push-button encryption: press the key on each adaptor and they'll jointly agree on and share a 128-bit AES encryption key. "

Oh, I wonder why they would need to use encryption? Oh, that's right, it's because the house wiring acts as a broadcast antenna (mains wiring isn't shielded) so any Tom, Dick or Harry can sniff your network from down the road.

It's just a shame that the group fighting against these devices seemed to have hired a web designer from 1997:

http://www.mikeandsniffy.co.uk/UKQRM/

I think a far more interesting story for the Reg to print would be about how these devices have been certified for use when they clearly and plainly cause problems to other SW band users. They are not fit for the purpose they are sold for.

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Split phases or transformers can be a hassle

Some (many?) people have split or two phases (two hot wires plus neutral) power line supplies and should these adapters be on different phases loss of signal can affect operation.

I solved this by using 0.1 ceramic capacitors between the phases to improve signal transmission.

Often power suppliers will equip street side transformers with similar devices on request if you want to connect across therm to, say, a neighbour.

If in doubt find an electronics technician - there should be a fuse or breaker protection between where the capacitor is attached and the meter - even it is on a shared circuit (i.e. doesn't have to be dedicated).

Switched power supplies in equipment can play heck with these devices, as can fluorescent lights.

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If Gbps PLT adaptors *don't* harm Radio 4....

Can you explain this, as well as interference to DAB?

http://www.youtube.com/watch?v=z3yVu5IfaEY

Gbps PLT based on the Gigle chipset operate from about 2-30MHz and 50-320MHz. The HF spectrum is notched in the Amateur bands, but the VHF spectrum in current products are not notched at all. The can lead to interference FM (whole band), CAA VHF and DAB to name a few services.

Gbps products have been tested in a UKAS laboratory and consistently fail EMC test specs that they claim conformance to. I can back up my argument; can you?

Also, I'd be interested in seeing a Reg Hardware test of these Gbps devices and actually demonstrate under real-world domestic conditions that the devices actually achieve anywhere near the throughput that they claim.

What is interesting is that domestic wiring and spurs become of resonant lengths at VHF, which means that a given Gbit PLT in the real world produces a non-deterministic RF transmitted spectrum from the wiring.

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@TeeCee re cost

TeeCee, I use Netgear XEB1004 85Mbps adapters that cost £75 the pair and have four Ethernet ports on each unit to connect my AV kit at the back of my telly to the Internet. The Nintendo Wii has Wi-Fi and no Ethernet so I leave it to its own devices but both the Xbox 360 and PS3 are connected over Ethernet. No doubt in time I will have a TV that uses Ethernet and if I update my superb WD TV to the new WD TV Live Plus that will also sprout Ethernet.

Why don't I just use wireless? I find it easier to use Ethernet for static devices as it is rock solid reliable and I have never noticed any problems as a result of using HomePlug. Also it beats the arse out of attempting to enter WEP/WPA security keys using a virtual keyboard to make a wireless connection with your games console.

In time I expect every device in my living room will demand an Interrnet Connection and I shall continue to use Ethernet rather than wireless wherever possible and I have no intention of stringing Ethernet cable around the house. HomePlug for me thanks.

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(Written by Reg staff)

Re: More info please

The UK edition has a standard UK three-pin plug.

Oh, and buy us a broad-spectrum analyser and we'll do the test.

FWIW, I've tested lots of these devices and had Radio 4 FM on in the background entirely without interference.

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